Surgical intervention is already known in patients afflicted with extremely severe obesity (morbid obesity), i.e. in the case of patients whose weight exceeds, for example, the ideal weight of at least 50 kg, by implanting gastroplasty rings in such patients. Such interventions not only allow a number of serious health problems resulting from such overweight to be avoided, but also, and especially, the certain and premature death of these patients can be avoided as well.
It is well known that patients suffering from morbid obesity experience a significant decrease in life expectancy, of at least ten to fifteen years, all the while suffering from significant psychological problems.
Moreover, a whole series of related health phenomena are implicated with this problem, such as cardiovascular troubles, hypertension, diabetes, and even severe arthritis.
It is also well known that, for such patients, treatments based on strict diets combined with a series of physical exercises, also associated with changes in behavior, specifically in nutrition, are generally poorly adapted, even if these treatment methods are acknowledges as being the most healthful.
This is the reason for which effective, long-term treatments for morbid obesity involve surgical intervention.
Generally speaking, we distinguish surgical treatment techniques involving a flaw in nutritional absorption, i.e. a shortening of the passage of foodstuffs and digestive successes, and techniques involving use of a gastric restriction that reduces the size of the stomach.
Surgical techniques involving a flaw in absorption are those involving, for example, a “by-pass” technique, or a bypass of the small intestine, or even techniques making use of a separation of the passage of foodstuffs relative to digestive successes.
These surgical techniques are relatively drastic and may give rise to severe complications, and this is the reason for which they are hardly ever used any more.
The tendency now is, in fact, to use surgical techniques implementing surgical interventions that are less drastic, such as gastric restriction involving placement of a gastric ring.
These techniques are now in common use, and for the most part make use of, as described for example in document WO-94/27504, a flexible band designed to be implanted around the stomach, forming a closed loop defining a fixed, pre-established ring parameter, thanks to a closure system. Against the surface that is intended to come into contact with the stomach, the body of the flexible band features, a variable-volume inflation chamber, which is linked to an adjustment catheter. This catheter allows injection or withdrawal of a fluid in the compression chamber, so as to vary the internal perimeter of the loop. This allows the diameter of the stoma to be changed or adjusted. In this way, in combination with the fixed, pre-established diameter of the ring, it is possible to regulate, however slightly, the diameter of the ring. This allows adjustment of the diameter of the stoma, and therefore adjustment of the quantity of foodstuffs ingested.
The closure system described in document WO-94/27502 makes use of a socket that is integral to one extremity of the flexible band. The opening of said socket extends tangentially from the ring and is shaped to cooperate with a profiled head that is integral to the second extremity of the flexible band, so that said head may be deformed in order to pass through the opening of the socket and create a thrust block against the edges of the socket, thus closing the ring with a latch closure.
Such a closure system has been shown to be impractical to implement during the latching operation of the ring around the patient's stomach.
In fact, in order to bring this operation to a satisfactory completion, the surgeon finds himself obligated to make special traction efforts in a direction tangential to the ring, corresponding to the direction in which the opening of the socket extends, in order to bring the head to cooperate with the socket. This effort's tangential direction corresponds, for the surgeon, to manipulations that are distinctly against and parallel to the stomach wall, which turns out to be difficult for the practitioner and risky for the patient, because it increases the risk that the practitioner will accidentally damage the stomach.
Moreover, in order to proceed with latching the ring, the surgeon finds himself restricted to blocking the extremity of the flexible band that has the socket, and to bring this extremity together to the second extremity featuring the head, then to engage the head in the socket by pulling directly on the second extremity, like for a sliding knot, until the latch engages by flexible joint
Thus, a risk exists that the surgeon might exert a traction force on the second extremity that is too hard, which would lead to damaging of the flexible band that forms the ring.
The drawbacks indicated above are exacerbated by the fact that the contoured head is lengthened by the diameter-adjustment catheter, which complicates the closure procedure even further, and which could lead to damage to the catheter.
Also, devices from within the prior art, such as that described in application WO-94/27504, have been shown to have drawbacks related to the difficulty in carrying out any surgical intervention which could come about after the gastroplasty implant.
In fact, it has been shown that, despite the possibility of changing, within certain limits, the diameter of the ring without surgical intervention, the installation of such gastric implants may sometimes be accompanied by intolerance phenomena, for example, vomiting linked to too great reduction in the diameter of the stoma, or even an ineffective action of the implant, linked to too great a diameter of the stoma, or yet again just a constraint, infection, or local or general inflammation.
This is the reason for which, in this case, it is necessary to intervene once again surgically, either to relieve the patient, or to adjust or change the gastroplasty ring that was previously implanted.
Such surgical interventions are particularly complex, and require complete opening of the ring, so as to change and replace it.
Standard system closures do not permit easy opening of the ring, for reasons similar to those leading to drawbacks encountered during closure of the ring.
Since that time, such post-implantation surgical interventions often lead to cutting of the ring by the surgeon, so as to change and replace it.
Finally, latching or unlatching of standard rings is therefore carried out by exerting opening or closing force, of a type like a traction force, directly on the flexible band itself. Such forces, generally exerted with the help of competing instruments, such as surgical pincers, may cause damage to the ring (tearing, piercing . . . ) which could render the ring non-functional.
The risk of occurrence of such problems is accentuated by the awkward opening/closing gesture required by such standard devices.
Moreover, implementation of a standard opening/closing system is particularly delicate, if not impossible, in the case of a ring whose diameter is controlled by an activating device making use of an actuator, of the type with an electric motor fitted to the flexible band that forms the ring. In fact, the rigidity of the motor block and its relative bulk prohibit all principles of opening or closing based on threading of one extremity of the flexible band into the other extremity, and/or a flexible connection of one extremity into the other.